In many fields of endeavor, such as in medicine, biological research, animal husbandry and other areas, there is a need to genetically stabilize, store and/or safely transport materials to offsite locations. These materials can include a wide variety of items, such as cultures of viruses and bacteria, tissue cells, multi-cellular organisms, enzymes, human and animal DNA, vaccines, diagnostic substrates, embryos, spermatozoa and a host of other materials.
In general, the process of genetically stabilizing organic or biological materials has been accomplished by containing the chosen materials in enclosures wherein cryogenic temperatures are maintained at or near liquid nitrogen or vapor phase liquid nitrogen temperatures. At a fixed location, there are currently means available to store and assure that the materials are properly and safely stored. However, when it is desired and/or necessary to transport the chosen materials to offsite locations, many problems and concerns arise. The biological materials must be transported at cryogenic temperatures to maintain viability. This requires a shipping container that can maintain a cryogenic environment for the duration of the transportation time and a means to assure that the contents of the shipper have stayed at or below a preset temperature level during the course of transportation.
As an example only, in the field of animal husbandry today, most domesticated animals, such as cows, turkeys and other animals, are artificially inseminated. In practice the sperm is collected and stored in what is known as straws. The straws are sealed, labeled and placed in a cylindrical tube. The tube is placed into a holder with the proper identification so that the person using the sperm to inseminate their animals can verify the origin of the sperm. The straws, tube and tube holder are then cryogenically stored in a container. This container has a compartment for holding the tubes and the compartment is surrounded by liquid nitrogen. The liquid nitrogen is contained by the container. To maintain the viability of the sperm, the sperm should be kept at temperature colder than minus 50 degrees centigrade. However, in practice most suppliers and users of animal sperm recommend that the sperm be kept no warmer than minus 90 degrees centigrade to assure the viability of the sperm.
To assure the end user that the temperature of the sperm has not dropped below a preset minimum, the shipping container that contains the tubes containing sperm straws also contains a device that acts as a temperature indicator. Today, the temperature indicator tube has two separate, partially liquid filled ampoules, one of the capsules is red in color and the other is blue. The red and blue capsules act as a go—no go indicator to assure the user that the frozen sperm has not dropped below a specified temperature, typically minus 90 degrees centigrade for the blue color and minus 50 degrees centigrade for the red color. If the blue liquid in the ampoule drops a certain amount, that is ok and the sperm is still viable. However, if the red ampoule drops then there is a problem with the temperature being below the desired threshold and the sperm is viewed as being: suspect.
Once a user chooses the type and quantity of sperm they need for their operations, the sperm supplier packages the sperm straws in the tubes and place the tubes in the containers with liquid nitrogen and the current temperature indicator and transports them offsite. As the container travels to its end destination, the container and its contents gets warmer and some of the liquid nitrogen evaporates off. In order not to create a buildup of pressure within the container, each container has a vent to release any nitrogen vapors. This creates a shipping problem as liquid nitrogen is a hazardous material when in liquid form. If the container should happen to tip over during transit, the liquid nitrogen could spill out through the vent hole, thereby causing a hazardous material (extreme cold) spill along with the potential for destroying the viability of the sperm.
Once the shipping container arrives at its destination, the user opens up the container and checks the temperature indicator to assure the viability of the sperm through the use of the colored go—no go type ampoule positions. Currently, this is a simple yes—no answer, the contents are either viable or not. The problem with the existing art is that it presents a simple go—no go gage for determining the viability of the contents of the container, whereas, in fact, there is a range of temperatures within which the contents of the container remain viable. As such, the existing art provides no means to determine the actual range of temperatures or actual temperature that the contents of the container reached over time and the possible viability of the contents. The new invention solves this problem.